Ortho-oxalic-acid ester of meta-cresol and process for the manufacture of the same.



UNITED STATES PATENT onnron.

LEOPOLD KAHL, OF NIEDEItAU,,NEAR DRESDEN, GERMANY, ASSIGNOR T0 RUTGERS-WERKE-ACTIENGESELLSCHAFT, OF BERLIN, GERMANY.

ORTHO-OXALIC-AGID ESTER OF META-CRESOL AND PROCESS FOR'THE MANUFACTUREOF THE SAME.

No Drawing.

Specification of Letters Patent.

Application filed June 21, 1909. Serial No. 503,303.

Patented May 28,1912.

and Process for the Manufacture of the Same, of which the following is aspecification.

The methods hitherto known for the production of phenol and cresolesters of oxalic acid consist in fusing phenol or cresol with oxalicacid at comparatively high tempera tures in the presence of dehydratingagents, (C. A. Bischofi' and A. v. Hedenstrom, Berz'chte dew Deut. Chem.Gas. 35, 3443), esters of oxalic acid being formed which. aredistinguished by their great stability. A further method for thepreparation of a cresol oxalic acid ester is described in thespecifications of German Patents 137584 and 141121. According to thismethod only an ester of p-cresol could'be obtained, which althoughotherwise relatively stable is distinguished by the extraordinary easewith which it can be saponified. According to the last namedspecification the meta-cresol forms no combination with oxalic acidunder the conditions of working given therein.

Now the method which forms the basis of the present invention has forits object to produce a combination with oxalic acid of the m-cresolalso, which of all the cresols possesses the most powerful disinfectingproperties.

If m-cresol be allowed to stand with anhydrous oxalic acid at asufficiently low temperature, viz. at about 15-25" (1., slow combinationof the cresol with the oxalic acid takes place, which finally leads tothe complete solidification of the Whole mass. The reaction productfreed from any excess of cresol that may be present by squeezing it outconsists of a body in .which oxalic acid and m-cresol are present in acombining ratio of 1 to. 2 and which at 51 C. melts and is at the sametime immediately decomposed into its components. The body is fairlyeasily soluble in water, and dissolves also in the usual organicsolvents, such as alcohol, ether, benzene, mostly with simultaneousdecomposition.

The comparatively easy decomposition of the body in conjunction with itscomposim-cresol, also creased disinfect-mg properties.

It is already known that the cresols.

tion is most easily explained by assuming the existence of anm-cresol-ortho-oxalic acid of the following formula:

The formation of the compound takes place according to the equation:

The new compound may be produced, for instance, by grinding together 216parts of m-cresol with 90 parts of anhydrous oxalic acid at atemperature of 15-20 C. and allowing it to. stand at this temperature,until the product of the reaction has become a dry powder. This is thedesired ester.

The present method enables the liquid mcresol, which of itself acts as apowerful disinfectant, to be converted into a solid compound which canbe easily produced in tablet form and which, compared with pure ossessesconsiderably inpossess in a high degree bactericidal properties, whichplace them in this respect at the head of bodies of the aromatic serieshitherto investigated. It is also known that of the .three isomers it isthe m-cresol which possesses the most powerful bactericidal propertieswith a relatively small poisonousness. The insolubility of the cresolsin general and of the m-cresol in particular in water stood in the wayof their use medicinally. Ohlmiiller, Laplace, Fr'zinkel and Jagerfound, it is true, that solutions of cresols in dilute hydrochloric andsulfuric acids can be prepared which possess great eflicacy againstcocci and spores; any medicinal application of these strongly acidsolutions could however scarcely be entertained.

An exceedingly eflicient disinfecting agent for medicinal use can beobtained according to -the present invention, seeing that it has beenpossible to bring the m-cresol, which is so efficient into a solid form.The m-cresol-o-oxalic acid ester is possessed of ta fla e, tha Phen lspecially high bactericidal properties, which mate.

The forms in which .the new disinfecting agent can be produced are vermanifold.

According to the purpose for w ioh it is tobe used it can be broughtinto the form of powder, tablets or solutions. For this pur' pose it isonly necessary to pulverize the pressed out ester, make it up in theform of tablets or dissolve it. In a gto 7} per cent. solutionmeta-cresol-ortho-oxalic acid ester almost instantly killsstaphylo-cocci,.which are capable of great resistance. It is thereorevery suitable for medicinal purposes, the disinfection of hands, etc.,as it can be used in combinations in which cauterizing actions areprecluded.

For the preparation of the m-cresol-ooxalic acid ester according to ,thepresent method the use of pure m-cresol as the initial material is by nomeans a necessity; on the contrary even commercial m-cresols orcommercial cresols containing a more or less large quantity of m-cresolcan be worked up into the ester. It is only necessary to and p-cresol heremoved first, say by treatin the commercial cresol mixture with anhynous oxalic acid or with oxalates, after which the residual cresols aretreated according to the present What I claim is:-

1. The process for the manufacture of a meta-cresol-ortho-oxalic ester,which consists in mixing meta-cresol with anhydrous oxalic acid andallowing the mixture to stand at 15-20 0., until the semi-liquid masshas become .solid, substantially as described.

2. As a new product, ,meta-cresohorthooxalic acid ester, containing twomolecules of metascresol and ;one molecule of oxalic acid in chemicalcombination, melting at 51 (1, while immediately decomposing intometa-,cresol and oxalic acid, s luble in water and in the usualsolvents, such as alcohol, ether and benzene, mostly with simultaneousdecomposition, and being suitable as a disinfectant.

In testimony whereof I have hereunto set my hand in presence .of twosubscribing witnesses.

, ISJZDQR BULL,

CARL ,HEm. p

